Explosion-engine.



PAiLENtrfBDA JULY 2, 19o?.

T. G. WRIGHT.,' EXPLOSION ENGINE.

APPLICATION Hmm JUNE 1.1905.

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TH: Nullus rlfrns un.. wasnmnmufma THOMAS G. WRIGHT, OF BRISTOL, ENGLAND.

EXPLOSION-ENGINE Specification of Letters LPatent.

Patented July 2, 1907.

Application filed Tune 1,1905. Serial No. 263,326.

England, have invented certain new and useful Improvements in and Relating to Explosion-Engines, of which the following is a specification.

This invention relates to internal combustion engines operating upon the Otto cycle, and has for its principal object to secure the effective scavenging of the products of combustion.

According to the invention I vary the strokes of the engine piston, so that upon the explosion stroke the piston shall travel to its extreme forward limit, uncovering a port or ports in the cylinder wall, and so that on the exhaust stroke the piston shall travel to its extremel backward limit into the combustion space and into immediate proximity lo the cylinder head. Frein this point the induction stroke connncnces, and continues to a point short of thc extreme forward limit of the piston travel, such that the port or ports referred to are not uncovered. On the compression stroke -the piston travel terminates at a point short of its extreme backward limit, leaving between the piston face and the cylinder head a space, into which the explosive charge is compressed. .By such means the products of combustion are completely discharged from the cylinder as far as is practicable, and provision is made within the cylinder itself for the compression ot' the explosive charge. It will thus be understood that in the application of the method of the invention to a motor in which the cylinder is tixed and the piston travel alone rendered variable, the induction stroke commences at the extreme end of the cylinder, and extends to a point. short of the extreme position the piston assumes at the end o the explosion stroke, the piston then returning in a short compression stroke and on the explosion stroke passing to the extreme forward limit of its travel, afterwards returning in the exhaust stroke to the extreme backward limit. Thus the compression stroke is a relatively short stroke, the exhaust stroke relatively long, and the induction and explosion strokes may be ci equal 0r unequal length, though taking.r place between different extreme positions of the piston within the engine cylinder.

lL will be understood that in operation the effect of the variation in the strokes of the engine piston as hereinbefore described will be that the engine piston, in reaching the extreme end of its forward travel, will uncover one or more exhaust or outlet port or ports, through which a portion of the products of combustion will escape, so that the return stroke will be performed to the extreme rearward limit of the engine cylinder 'and the exhaust gases be completely expelled as far as is practicable with less back pressure than if the preliminary release through the port or ports aforesaid had not been effected. By such means the pure combustible charge entering the cylinder on the induction stroke is not subject to admixture or contact with the products of the previous explosion. Is will furthermore be understood that by the reduction in length of the induction stroke, the exhaust or outlet port or ports will not be uncovered during the induction stroke.

An engine constructed to operate upon the method of the present invention is illustrated byway of example in the accompanying drawing,r in which,

Figure l is a sectional elevation of an engine provided with gear to give the cycle of operation according to the invention, the piston being shown at the end of its exhaust stroke. Figs. 2, 3 and 4 are diagrammatic views showing the position of the piston and mechanism respectively at the end of the induction stroke, at the end of the compression stroke, and at the end of the explosion stroke. Fig. 5 is a detail sectional elevation ou the lino at-x (Fig. l), while Fig. (i is a detail section on the lino .'r-y tFig. l).

In the engine illustrated in Figs. ll to It of the accompanying drawings, a series oi holes h are provided iu the cylinder which are uncovered bythe engine piston f at the end of the explosion stroke. The cylinder cover a. is provided as a casing for the reception of the exhaust valve c and the inletvalve b respectively. Upon the crank pin an eccentric bush j is provided having a toothed wheel or ring j integrally formed with it, the toothed wheel or ring bt ing concentric with the crank pin k. The toothed wheel or ring j meshes with the pinion t which is secured upon the extreniity of a spindle m/ passing through the tiy wheel r, the said spindle carrying the toothed wheel in. upon tho other side of the said ily wheel. The toothed wheel m gears with a pinion n which is fixed to the crank casing q and is mounted upon the crank axle p.

It will be und crstood that the gear ratio of the toothed wheels aforesaid is such that when the fly wheel r is rotated once the eccentric bush and toothed wheel j and j make one hali a revolution. The connecting rod is mounted upon the eccentric bush j, and on the rotation of the crank shaft a variable movement is communicated to the piston as represented in Figs. l to 4.

lt will be understoid that in Fig. l, in which the piston is shown at the end of the exhaust stroke, the piston f is in immediate proximity to the cylinder wall or cover a, the exhaust gases ha ving been expelled through on the opening of the exhaust valve c.

In Fig. 2 the piston f is indicated at the lowest position it assumes short of uncovering the exhaust ports h, and in this position it will be understood that the eccentric bush j llas made a quarter of a revolu \n upon the crank pin k.

In Fig. 3 the piston] is indicated at the end oi hc compression stroke at a position short of the extreni. iongth of its movement upon the exhaust stroke. This whereby a suliicient space is left in the cylinder in which the explosive charge may be compressed. l

Fig. 4 illustrates the piston at the termination of the explosion stroke, where it assumes the extreme position of its forward travel in advance of the position indicated in Fig. 2, this resulting from the fact that the eccentric bushj has traveled round into a position to bring the piston further forward.

It will be understood that theseresults are obtained in consequence of the eccentric bush having been placed, as in Fig. 1, at the termination of the exhaust stroke7 where, with the piston at its nearest point to the cylinder head, the throw of the eccentric bush is not setl on the line but a little behind it, the variations at the opposite end of the strokes being dependent upon this displacement.

It is obvious that tl1e`method of the invention may be carried into effect by mechanism or means substantially the same as that hereinbel'ore described without departing from the invention.

What I claim as my invention and desire to secure by uLetters Patent is.

In an internal combustion engine operatingy on the Otto cycle the provision of two exhaust outlets one near the front end of the cylinder' and provided to be uncovered by the piston on its movement toward the extremity of the explosion stroke, and the other provided at the rear ot' the cylinder' und controlled by a valve and menus for giving to the piston a variable stroke whereby the exhaust outlet toward the` front end of the cylinder is uncovered by the piston only toward the end of the explosion stroke while being covered throughout the induction stroke substantially as described.

in testimony whereof I have signed my name to this specification in the presence ot' two subscribing witnesses.

T. G, WIIUHIT.

Witnesses M. B. WRXGHT, JOHNLEE Osuoux. 

